Floor furnace



Oct. 30, 1945.

Filed June 24, 1.942

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FLOOR FURNACE Filed June 24, 1942 3 Sheets-Sheet 2 63 IETOR Hmb 056 00/081 @M mu ATTORN EY Oct. 30, 1945. A. D; LDs 2,387,939

FLOOR FURNACE Filed Jl me 24, 1942 3 Sheets- Sheet 5 J at INVENTORfimbrose 0. 0/03 wwm ATTORNEY Patented Oct. 30, 1945 FLOOR FURNACEAmbrose Dean Olds, Wichita, Kans., assignor to The Coleman Lamp andStove Company, Wichita, Kans, a corporation of Kansas Application June24, 1942, Serial No. 448,273

Claims.

This invention relates to floor furnaces, and more particularly to aninner casing and liner construction therefor. It is well known thatfurnaces of this character are noisy in operation for the reason thatuneven expansion and contraction of the inner casing and its liner causelarge flat areas thereof to buckle and snap out of their normalpositions.

Therefore, the principal object of the present invention is to providean inner casing and liner construction which permit uneven expansion andcontraction without producing objectionable noises.

Other objects of the invention are to provide a liner composed of aplurality of sections each having independent movement relative to theother; to provide the liner sections with channel-like ribs that areformed therein to accommodate linear expansion and contraction of theintermediate plane portions of the sections in a direction transverselyof the ribs; to provide for relatively loose connection of the expansionribs with the inner casing to accommodate expansion of the sections in adirection longitudinally of the ribs; and to provide slight spacing ofthe adjacent edges of the liner sections so that the sections may moveto and from each other without touching and creating buckles therein asmight be the case when expansion of one section is limited by anadjacent section.

Other objects of the invention are to provide an inner casing and linerassembly loosely suspended within the outer casing; and to provide arelatively strong casing structure having flexibility at the corners tofurther reduce noises incidental to buckling of the side walls of thecasings caused by their inability to have some movement relatively toeach other.

In accomplishing these and other objects of the invention, I haveprovided improved details of structure, the preferred forms of which areillustrated in the accompanying drawings, wherein:

Fig. 1 is a perspective view of a floor furnace embodying the featuresof the present invention, parts being broken away to better illustratethe construction.

Fig. 2 is an enlarged fragmentary perspective view of the supportingflange for the outer casing.

Fig. 3 is a horizontal section through the upper portion of the furnace,with the heating unit and one corner of the inner casing being shown inplan.

Fig. 4 is an enlarged horizontal section through one corner of the innercasing, particularly illustrating the liners and flexible mountingthereof.

Fig. 5 is a vertical cross-section through the furnace with the heatingunit shown in elevation.

Fig. 6 is a detail perspective view of one upper corner of the innercasing.

Referring more in detail to the drawings:

l designates a floor furnace embodying the features of the presentinvention and which includes an outer casing 2, an inner casing 3, and aheating unit 4 supported by the outer casing and enclosed in the innercasing.

The outer casing 2 includes substantially rec tangular side and endwalls 5 and 6 formed of sheet metal and having the corners thereofconnected together by means of lock seams l, the seams being formed byproviding the adjacent edges ofeach sheet with hook-like flanges 8 and 9interengaged with each other as best illustrated in Fig. 2. While thehook-like flanges are sufficiently close to prevent leakage through thejoint, they provide substantial movement of the side and end wallsrelative to each other so as to reduce buckling of the sheets and metalnoises incidental to heating and cooling of the furnace. The seams thusdescribed provide for substantially greater rigidity of the casing inthe vertical direction thereof and greatly enhance strength of thecasing for a given gage metal. The upper edges of the side and end wallsare formed outwardly and laterally vn'th respect to the planes of thesheets, as at l0, and then inwardly, as at H,

toward the plane of the sheets to provide a marginal supporting flangel2 of double thickness of metal l3 and [4.

The ends of the upper ply l3 of the flanges are cut away from the cornerseams of the casing as indicated at I5, Fig. 2, and the lower plies Mare cut shorter to attach angle-shaped corner plates Hi. The cornerplates l6 are of heavier gage metal and have leg portions I1 and I8bridging the space between the adjacent ends of the upper plies l3 ofthe flanges and are attached to the under side thereof by spot weldingor the like as indicated at I9. The angle members l6 thus cooperate withthe lateral flanges to form a substantially rigid rectangular frameaboutthe upper portion of the outer casing to maintain the rectilinearshape thereof and provide a support for the furnace whereby it issuspended within a floor opening as illustrated in Figs. 1 and 5.

The bottom of the outer casing is enclosed by a pan-like member 20having parallel troughlike air directing portions 2| and 22 extendingparallel with the side walls 5 and spaced apart to accommodate a flatsurface 23 for supporting the heating unit 4 substantially in the planeof the lower edges of the side an'dend walls as best illustrated in Fig.5. The supporting portion 23 has an elongated opening 24 extendinparallel with the trough portions 2I-22 to accommodate the burner 25 andprovide for inlet of combustion supporting air to the combustion chamberof the heating unit later described.

The burner 25 may be of any approved construction and suitably supportedby brackets 26 from the bottom member 20 as illustrated in Fig. 5. Themarginal edges of the bottom member are flanged outwardly and upwardlyto provide a marginal seat 21 to engage the lower edges of the side andend walls which are preferably bent reversely, as at 23, to cooperatewith the marginal flanges 29 of the bottom in maintaining therectilinear shape of the casing, the flanges 29 being attached to theside and end walls, for example by spot welding or the like.

The trough-like portion 2| is relatively wider than the trough portion22 and the opening 24 is offset laterally from the longitudinal medianline of the bottom member so as to accommodate the combustion chamber 30of the heating unit 4 and a laterally supported radiator 3| which isspaced from the combustion chamber to form an updraft passageway 32therebetween.

The combustion chamber and radiator units may be of any approved designbut in the illustrated instance the combustion chamber is shown asformed of a pair of mated pan-shaped members 33 having marginal flanges34 on the vertical and upper edges thereof, which are welded together toform a gas-tight combustion chamber. The bottom of the combustionchamber is in open registry with the opening 24 and has an angle frame35 arranged with a flange 36 seating upon the supporting portion 23 ofthe bottom and secured thereto by suitable fastening devices such asscrews 31, a suitable gasket 38 being inserted therebetween.

The radiator unit 3 is of similar construction but the lower portionthereof is closed to provide an interior passageway for the hot productsof combustion discharged from the upper portion of thecombustion chamberthrough laterally extending connections 33 as best shown in Fig. 3.After circulation of the hot products of combustion through the radiatorchamber they are discharged from the lower portion thereof through aduct 40 extending through a notch 4! in the inner casing and aregistering opening 42 in the outer casing to connect, through a draftdiverter 43, with a vent pipe 44 leadin to a chimney (not shown). Thelower portion of the radiator unit is preferably braced upon the angleframe 35 by means of brackets 45 as best shown in Fig. 5.

The inner casing 3 and its liner constitute the principal feature of thepresent invention and the casing includes side and end walls 46 and 41spaced inwardly from the corresponding walls of the outer casing to formdowndraft passages 48 therebetween. The walls of the inner casing are ofshorter height than those of the outer casing so that the lower edgesthereof are spaced from the bottom member to provide a connection 49between the lower ends of the downdraft passages and updraft passages 50surrounding the heatin unit. The upper portions of the side and endwalls are flared inwardly to provide a slightly restricted outlet 5| forair moving upwardly around the heating unit and enlarged inlets 52 forthe downdraft passages 48.

The walls of the inner casing are also formed of sheet metal and joinedtogether by lock seams 53 similar to the comer seams of the outer casingto provide flexiblity at the corners and at the same time enhancerigidity thereof in the vertical direction of the casing. The inwardlyflaring portions of the end walls have flanges 54 overlapping thecorresponding portions of the side walls as illustrated in Fig. 6, theflanges being spot welded to cooperate with the lock seams in completinginterconnection of the side and end walls.

To prevent overheating of the downdraft passages and insure freecontinuous flow of cool air into the furnace. the inner casing isprovided with a lining 55 that cooperates with the side walls of theinner casing to provide for flow of live air through the passageway 56therebetween and thereby insulate the inner casing from heat radiated bythe heating unit. Since the linings of floor furnaces are locateddirectly facing the hot surfaces of the heating units, and since thewalls of the inner casing are supported in a substantially cooler zoneand contacted by relatively cool air moving through the downdraftpassageways, the liners have uneven expansion and contraction relativeto the inner walls of the easing. Consequently much difficulty has beenencountered in the construction of floor furnaces because unevenexpansion and contraction cause the large flat areas of the inner liningor casing to buckle and cause disagreeable snapping and booming noiseswhen the furnace heats and cools. In order to overcome this difficulty,the lining in the present structure is provided with vertically arrangedribs 51 which also form spacers to maintain a positive spacing betweenthe lining and walls of the inner casing.

In the illustrated instance the ribs 51 have an isosceles trapezoidcross-section and are formed by providing the lining sheets with spacedvertical bends 58 to form slightly converging leg portions 59 for thesides of the ribs and connecting portions '50 forming the bottoms of theribs, the portions 60 being arranged to lie against the walls of theinner casing and adapted to have slight movement relative thereto. Theribs are secured to the inner casing by connections 6| to allow movementof the lining sheets in a direction parallel with the ribs. Theseconnections may be of any type that will allow independent movement ofthe lining such as wire stitches, which are illustrated in thedrawings,' a wire being formed into staples having leg portions 62loosely extending through openings 63 in the side walls of the innercasing and through registering openings 64 in the bottoms of the ribs sothat the ends may be loosely clinched as at 65. The lining may thus havelinear movement on the walls of the inner casing in all directions.Therefore, the body portions or the flat areas of the liningintermediate the ribs maintain their normal plane-like shape and are notbuckled because of inability to move with re spect to the inner casing.

In order that the lining on the side and end walls will have relativemovement with respect to each other, the lining is formed in sections,for example, one for each side and end wall, with their adjacent edgesflanged outwardly, as at 56 and 61, and spaced apart, as at 68. Whenthus spaced the sections expand freely without interference as would bethe case if the corners were connected.

While the ribs in the lining eliminate disagreeable metal noises usuallyencountered in floor furnace construction, they also have the functionof l providing greater surface area for absorbing radiant heat and ivegreater contact of the circulated air, thereby increasing efficiency andat the same time permitting the furnace to operate at lower workingtemperatures.

In order to further increase the heating area contacted by the upwardlymoving air stream, the space 32 between the combustion chamber andradiator is divided by a heat converter 69 comprising a sheet metalplate having a series of vertically arranged corrugations or ribs '10.The plate is retained in proper position by arms II that are welded tothe flange seams of the combustion chamber. The diverted plate .absorbsradiant heat from both the combustion chamber and radiator unit andpasses the heat units into the flowing air moving upwardly therebetween.The diverter plate thus reduces heat loss through the chimney andresults in lower fuel; cost. The open top of the outer casing is closedby the customary floor grill l2. j

The inner casing is floatingly suspended within the outer casing bymeans of studs 13 extending laterally from the end walls near the upperportions thereof and which are supported within notches N of inwardlyextending brackets attached to the inner face of the end walls of theouter casing. The notches," opening upwardly, permit removal of theinner casing through the open top of the outer casing upon removal ofthe grill. This floating suspension of the inner cascasings provide forsufficient flexibility to avoid noises that are usuallyproduced in theinner and outer casings of a floor furnace.

What I claim and desire to secure by Letters Patent is:

1. In a floor furnace, an inner casing comprising, sheet metal end andside walls, individual liner sections for said walls having the adjacentside edges of adjacent liner sections unconnected and completely spacedfrom said casing and from each other to permit independent movement ofthe liner sections relative to each other responsive to uneven expansionand contraction of the liner sections with respect to said walls of thetrimer casing when the floor furnace is in opera- 2. In a floor furnace,an inner casing comprising, sheet metal end and side walls, linersections for said end and side walls having adjacent side edges spacedapart to permit independent movement of the sections relative to eachother responsive to uneven expansion and contraction of the linersections with respect to said walls of the casing, and means looselysupporting said sections on the respective side walls of the easing forrelative movement of the sections in directions parallel with saidspaces between the liner sections to compensate for uneven expansion andcontraction of said liner sections with re- 01' spect to the casingwalls without buckling of the "liner sections between the points ofsupport on ing within the outer casing provides independent movementbetween the respective casings so as to avoid any stresses tending tocause snapping and booming noises of the sheets composing the side wallsthereof.

In operation the hot gases moving into contact with the interior of thecombustion chamber and radiator 3i heat the surfaces thereof, which heatis picked up by the air surrounding the heating unit 5, causing a riseof temperature within the inner casing 3 so that the colder, heavier airin the downdraft passages E1 causes upward displacement of the heatedair through the central portion of the grill, thereby setting upcirculation from the room downwardly through the marginal edges of thegrill, through the downdraft passageways 48 for deflection upwardly bythe trough-like portions 2! and 22 into the updraft passagewayssurrounding the heating unit. That portion of the heat which is radiatedfrom the hot surfaces of the heating unit is absorbed by the lining sothat it is picked up by the air moving in contact with the respectivesides of the lining. The portion of the air which moves upwardly throughthe spaces between the liner and the walls of the inner casing carriesaway the heat of the liner with sufficient rapidity to avoid heating ofthe air in the downdraft passages 38. The heat converter 69 also absorbsradiant heat which is taken up by the air moving thereover so that theheat loss through the chimney is reduced to a minimum.

As the lining is carried at a higher temperature than the walls of theinner casing, it has uneven expansion and contraction with respectthereto, upon heating and cooling of the furnace, however, the laterallyflexible ribs and the loose support thereof on the inner casing providefor sufficient movement of the flat plane portions to avoid bucklingwhich causes the usual booming and snapping noises. The spaced edges ofthe individual liner members provide for free movement of one liner withrespect to the adjacent liner. The lock, corners of the inner and outerthe casing.

3. In a floor furnace, an inner casing comprising, sheet metal end andside walls, liner sections for said end and side walls having adjacentside edges spaced apart to permit independent movement of the sectionsrelative to each other responsive to uneven expansion and contraction ofthe liner sections with respect to said walls of the casing, and meansloosely su porting said sections on the respective side walls of theeasing for relative movement of the sections in directions parallel withsaid spaces between the liner sections to compensate for unevenexpansion and contraction of said liner sections with respect to thecasing walls without buckling of the liner sections between the pointsof support on the casing, said liner sections having transverselyflexible ribs to compensatefor uneven expansion when the liner sectionsmove to and from each other.

4. In a floor furnace, an inner casing assembly including interconnectedside and end walls, a liner section for each of said walls havingtransversely flexible ribs spacing the major portions of said liningfrom the walls of the casing to compensate for uneven expansion of thelining with respect to the casing in directions transversely of saidribs, said liner sections having adjacent side edges spaced apart, andmeans loosely connecting the ribs with the casing to support said liningfor limited movement to compensate for uneven expansion and contractionof the lining in a. direction longitudinally of said ribs.

5. In a floor furnace, an inner casing assembly including side and endwalls connected by lock seams to form flexible corners for said casing,separate liners for the side and end walls of the casing having spacedtransversely flexible ribs spacing the major portions of said linersfrom the casing, and means loosely connecting the ribs with the walls ofthe casing to support said lining within the casing, said liners beingspaced apart adjacent said lock seams.

6. In a floor furnace, an outer casing, an inner casing, meanssuspending the inner casing for support within the outer casing withwalls of the inner casing spaced from corresponding walls of the outercasing, a. liner for the inner casings including a plurality of flexiblesections unattached with respect to each other and having adjacent sideedges spaced apart and out of contact with each other and the innercasing and with the side edge of one section located in a differentplane than the adjacent side edge of the next adjacent section.

'7. In a floor furnace, an outer rectangular casing, an innercorrespondingly shaped casing supported within the outer casing withwalls of the inner casing spaced from corresponding walls of the outercasing to provide downdraft passages therebetween, a, heating unit inthe inner casing, a liner section for each wall of the inner casing andhaving ribs extending parallel with the downdraft passages to space bodyportions of the sections from said walls of the inner casing and to formpassageways for insulating the downdraft passages from excessive heatingby said heating unit, and means supporting the liner on said innercasing, said sections having adjacent vertical side edges slightlyspaced apart to permit expansion of the sections.

8. In a floor furnace, an outer casing, an inner casing, meanssuspending the inner casing for floating support within the outer casingand with walls of the inner casing spaced from corresponding walls ofthe outer casing to provide downdraft passages therebetween, a heatingunit in the inner casing, a liner between the inner casing and theheating unit and having ribs extending substanthe adjacent side edge ofan adjacent section to permit expansion of the sections.

v 9. In a floor furnace, an outer casing, an inner casing supportedwithin the outer casing with walls of the inner casing spaced fromcorresponding walls of the outer casing to Provide downdraft passagestherebetween, a heating unit in the inner casing, a liner between theinner casing and the heating unit and having ribs extending parallelwith the downdraftpassages to space bodyportions of the liner from saidinner casing and to form passageways for insulating the downdraftpassages from excessive heating by said heating unit, and fastenersextending relatively loosely through the inner casing and said ribs forsupporting the liner on said inner casing for limited independentmovement thereon responsive to expansion and contraction incidental toheating and cooling of the furnace, said liner being composed of aplurality of sections slightly spaced apart with the edges of adjacentsections located in different tiall parallel with the downdraft passagesto space body portions of the liner from said inner casing and to formpassageways for insulating the downdraft passages from excessive heatingby said heating unit, and means supporting the liner on said innercasing, said liner being composed of a plurality of sections havingadjacent side edges slightly spaced apart with the side edge of oneadjacent section in a different plane than planes to permit expansion ofthe sections.

10. In a floor furnace, an outer casing, an inner casing supportedwithin the outer casing with walls of the inner casing spaced fromcorresponding walls of the outer casing to provide downdraft passagestherebetween, a heating unit in the inner casing, a liner between theinner casing and the heating unit and having transversely flexible ribsextending parallel with the downdraft passages to space body portions ofthe liner from said inner casing and to form passageways for insulatingthe downdraft passages from excessive heating by said heating unit, andmeans loosely supporting the liner on said inner casing for independentmovement thereon and cooperating with said ribs to avoid buckling ofsaid lining and inner casing responsive to expansion and contractionincidental to heating and cooling of the furnace, said liner beingcomposed of a plurality of sections slightly spaced apartwith the edgesof adjacent sections located'iin-diflerent planes to permit expension ofthesections one relatively to the other.

AIHBROSE DEAN OLDS.

